NDE of Steel Gas Pipelines Using Magnetostrictive Sensors. Final Report, August1994-July 1995

摘要

The feasibility of applying a new nondestructive evaluation (NDE) technique,termed 'magnetostrictive sensor (MsS),' to a long-range, 100-percent volumetric inspection of relatively large-diameter pipes was investigated experimentally. With this technique, elastic waves are launched along the length of pipe, and signals reflected from defects are defected using MsSs which are noncontacting and, thus, require no couplant. Results obtained from 16-inch-outside-diameter, 3/8-inch-wall pipes demonstrated well the applicability of the technique to large-diameter pipes used in transmission pipelines for detection of various defects such as metal loss due to corrosion, circumferential cracks, mechanical damage, and coating disbondment. The technique was also shown to be applicable from both the inside and the outside of the pipe. Areas of potential pipeline NDE applications were identified and discussed.